BLE Scanner does not work

[Schoeppi93]

Hi @konne ,

I tried to use the ble scanner in node RED and unfortunately I did not get it to work.
My configuration node:

My reader node:

The BLE config block recognizes devices, but after the reader block does not pass data to it's output.

When the ble scanner is added, the victron ble scanner node does also stop working. After a restart of the Cerbo the victron ble scanner starts to work again, but the generic ble scanner does not work.

Maybe you see some obviuos configuration issues?

Thanks for creating that package in general! And thanks for your support!

Kind regards,
Felix

[konne]

@Schoeppi93 Hi Felix,

thank for your tests. I'm currently until the 23th on a Business trip and can not really test it.
I will try my best in the next days to check what could be the issue.

Can you login into your device via SSH?
Can you try the following command line commands:

node ./bin/ble-reader.js discover
node ./bin/ble-reader.js read --debug
node ./bin/ble-reader.js read --bluetooth bluez --debug
node ./bin/ble-reader.js read "My BLE Device" --interval 5

And share the results with me.

thanks Konrad

[Schoeppi93]

Hi konne,
no worries! I'm super thankful for your work here. Each time I tried to contribute on open source projects in my free time I found it super hard to get things done/take the time in general.

I used my raspberry pi 4 system for the debugging, it shows the same behaviour:

I searched the filesystem on Venus OS and found the file without file extension here:

Thats also runable:

For:

• node ./bin/ble-reader.js read --debug
• node ./bin/ble-reader.js read --bluetooth bluez --debug
  They time out connecting:

root@raspberrypi4:~# node ./node_modules/.bin/ble-reader read --debug
Error: Timed out after 15000ms during BlueZ Device1.Connect().
    at Timeout._onTimeout (file:///data/home/root/node_modules/node-red-contrib-ble-scanner/dist/ble/bluez.js:294:49)
    at listOnTimeout (node:internal/timers:581:17)
    at process.processTimers (node:internal/timers:519:7)

• node ./bin/ble-reader.js read "My BLE Device" --interval 5
  returns empty:

root@raspberrypi4:~# node ./node_modules/.bin/ble-reader read "My BLE Device" --interval 5
[]

[konne]

Hi Felix,

thanks, this helps a lot.

First small thing: for the read command, please use the exact name field from the discover output. In your screenshot, the ThermoBeacon entry is:

"name": "ThermoBeacon"

So the command should be:

node ./node_modules/.bin/ble-reader read "ThermoBeacon" --debug

The other important test is whether BlueZ itself can connect to the device. Your discover output shows this MAC address:

78:9F:00:00:13:EB

Can you please run this directly on the device?

bluetoothctl connect 78:9F:00:00:13:EB

If this also times out or fails, then the issue is not the Node-RED node yet. It means BlueZ can see the ThermoBeacon advertisement during discovery, but cannot establish a GATT connection to it.

[Schoeppi93]

Hi @konne ,

sorry, my bad. Should have been obvious to use my desired device name there:

root@raspberrypi4:~# node ./node_modules/.bin/ble-reader read "ThermoBeacon" --interval 5
Error: Missing BLE notify characteristic fff1 via BlueZ. Found: 2a05, 2a23, 2a24, 2a25, 2a26, 2a27, 2a28, 2a29, 2a2a, 2a50, fff3, fff5
    at buildBluezCharacteristics (file:///data/home/root/node_modules/node-red-contrib-ble-scanner/dist/ble/bluez.js:157:15)
    at Object.connectBluezDevice [as connect] (file:///data/home/root/node_modules/node-red-contrib-ble-scanner/dist/ble/bluez.js:110:39)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async connectDevice (file:///data/home/root/node_modules/node-red-contrib-ble-scanner/dist/reader.js:67:21)
    at async connectReaders (file:///data/home/root/node_modules/node-red-contrib-ble-scanner/dist/reader.js:54:26)
    at async readAtInterval (file:///data/home/root/node_modules/node-red-contrib-ble-scanner/dist/cli.js:107:21)
    at async Command.<anonymous> (file:///data/home/root/node_modules/node-red-contrib-ble-scanner/dist/cli.js:37:9)
    at async Command.parseAsync (/data/home/root/node_modules/commander/lib/command.js:1122:5)
    at async main (file:///data/home/root/node_modules/node-red-contrib-ble-scanner/dist/cli.js:40:9)

debug option gives the same output.

Connection is possible:

root@raspberrypi4:~# bluetoothctl connect 78:9F:00:00:13:EB
Attempting to connect to 78:9F:00:00:13:EB
Connection successful
AdvertisementMonitor path registered

Seems like I have to use an other notify UUID. I have no clue of BLE notifi IDs to be honest, but I will try letting Claude fix that.

Using another ID basically works (with no data):

root@raspberrypi4:~# node ./node_modules/.bin/ble-reader read "ThermoBeacon" --interval 5 --notify-uuid 2a05
[
  {
    "device": {
      "id": "/org/bluez/hci0/dev_78_9F_00_00_13_EB",
      "address": "78:9F:00:00:13:EB",
      "addressType": null,
      "name": "ThermoBeacon",
      "rssi": null,
      "backend": "bluez"
    },
    "timestamp": "2026-06-02T17:10:45.922Z",
    "notifyUuid": "2a05",
    "messages": []
  }
]

Okay, got it.
The ThermoBeacon does not use GATT, but sends the whole data in the advertisements manufacturer data. I can grab it with btmon:

@ MGMT Event: Device Found (0x0012) plen 68                                                   {0x0001} [hci0] 14.629829
        LE Address: 78:9F:00:00:13:EB (OUI 78-9F-00)
        RSSI: -48 dBm (0xd0)
        Flags: 0x00000000
        Data length: 54
        Flags: 0x06
          LE General Discoverable Mode
          BR/EDR Not Supported
        16-bit Service UUIDs (partial): 1 entry
          Unknown (0xfff0)
        Company: Mitel Semiconductor (16)
          Data: 0000eb1300009f7893016b2000007201170b0000
        Name (complete): ThermoBeacon
        Peripheral Conn. Interval: 0x0018 - 0x0138
        TX power: 0 dBm

[konne]

@Schoeppi93 thanks for your tests. I created a new 0.2.0 release.
https://flows.nodered.org/node/node-red-contrib-ble-scanner

Please test and share you results

[Schoeppi93]

Unfortunately some updated dependencies seem to require a newer node red engine than the one embedded in Victron venus OS:

[konne]

Thanks for reporting this. The issue was commander@15, which requires Node >=22.12.0 and therefore breaks on Node 20 based images.

I changed the package back to the Node 20-compatible Commander 14.x line and released it as 0.3.0:

• PR: Restore Node 20 compatible commander #9
• Release: https://github.com/node-red-contrib/node-red-contrib-ble-scanner/releases/tag/0.3.0

I also checked the dependency lockfile for packages that reject Node 20 entirely; after the change there are none, and the test suite passes under Node 20.20.2.

Could you please test again with 0.3.0?